F3 Uranium Reports Broad High-Grade Uranium Intersections at Tetra Zone as Follow-Up Drilling Gets Underway

• PLN25-219A returned a 13.0-metre interval averaging 0.28% U3O8, with 4.5 metres of composite high-grade sub-intervals, on the Tetra Zone of the Broach Property
• The strongest sub-interval graded 3.0 metres at 1.19% U3O8, including a 0.5-metre section at 2.08% U3O8
• PLN25-221, drilled approximately 75 metres to the east on a new grid line, confirmed uranium mineralisation and established east-west zone continuity
• A follow-up drill programme with one diamond drill is currently active at the Tetra Zone
• The Tetra Zone sits within F3's 42,961-hectare Patterson Lake North Project in the Western Athabasca Basin, near Paladin Energy's Triple R and NexGen Energy's Arrow deposits

F3 Uranium Corp. (TSXV: FUU) (OTCQB: FUUFF) is a Canadian-based uranium exploration and development company focused on the high-grade JR Zone and the Tetra Zone, its newest discovery located 13 kilometres to the south on the Broach Property, both within its Patterson Lake North (PLN) Project in the Western Athabasca Basin. The company holds three 100% owned properties in the Athabasca Basin: Patterson Lake North, Minto, and Broach, covering a combined 42,961 hectares. The western Athabasca Basin in Saskatchewan is home to some of the world's largest high-grade uranium deposits, including Paladin Energy's Triple R and NexGen Energy's Arrow projects.

PLN25-219A Returns Broad 13.0-Metre Interval with Multiple High-Grade Sub-Intervals Confirming Tetra Zone Mineralisation

Drill hole PLN25-219A, drilled on the 075W grid line, produced the headline result of the Fall 2025 Tetra Zone programme. The hole returned a main mineralised interval of 13.0 metres grading 0.28% U3O8, the standard measure of uranium content in rock. Within that interval, the hole contained 4.5 metres of composite high-grade mineralisation spread across three distinct sub-intervals.

To put the grades in context, F3 classifies any result above 1.0% U3O8 as high-grade uranium mineralisation. Assay results are determined by laboratory analysis of split drill core samples, which measure uranium concentration at specific depth intervals. The three high-grade sub-intervals within PLN25-219A were: 3.0 metres at 1.19% U3O8, including 0.5 metres at 2.08% U3O8; 0.5 metres at 1.07% U3O8; and 1.0 metre at 1.60% U3O8.

PLN25-219A also intersected lower-grade mineralisation above and below the main interval: 1.0 metre at 0.09% U3O8, 4.0 metres at 0.09% U3O8, and 4.0 metres at 0.10% U3O8. All depth measurements reported are down-hole and true thicknesses have yet to be determined.

PLN25-221 Confirms Zone Continuity, Providing Key Geological Insight into Tetra Zone Controls and Geometry

PLN25-221 was drilled on the 000 grid line, approximately 75 metres east of PLN25-219A. The hole was part of the same Fall 2025 programme and tested whether uranium mineralisation at the Tetra Zone extends laterally along an east-west axis. Grid lines are reference coordinates used to organise and map drill hole locations across a project area.

The hole returned two mineralised intervals: 1.0 metre at 0.13% U3O8 and 4.5 metres at 0.10% U3O8. The detection of mineralisation on the 000 grid line confirms that the Tetra Zone extends eastward from the 075W line, where PLN25-219A was drilled.

Together, PLN25-219A and PLN25-221 provide geological data on the controls and geometry of the Tetra Zone. The 000 grid line result contributes to mapping the spatial extent of the zone and informs how future drill holes are positioned within the programme.

Follow-Up Drill Programme Now Underway to Further Define the Newest Discovery on the Patterson Lake North Project

A follow-up drill programme is currently in progress at the Tetra Zone using one diamond drill. Diamond drilling extracts a continuous cylinder of rock from underground, allowing geologists to examine the rock directly and measure uranium content at precise depth intervals. This method is standard practice for advancing an exploration discovery.

The Tetra Zone, first announced as a discovery in November 2025, is located on the 19,022-hectare Broach Property, 13 kilometres south of F3's JR Zone on the PLN Property. The PLN Project covers 42,961 hectares in total and sits just within the south-western edge of the Athabasca Basin. All three properties comprising the PLN Project are accessible via Provincial Highway 955.

VP Exploration Sam Hartmann commented: 

"We are pleased to release the final assays for Tetra Zone from the Fall 2025 program. PLN25-219A returned a broad 13.0-metre interval grading 0.28% U3O8 that includes several higher-grade sub-intervals, totaling 4.5m of composite high-grade mineralization. These results, together with the confirmation of continuity in PLN25-221, provide important geological information that will help refine our understanding of the Tetra Zone's controls and geometry. A follow-up drill program is currently in progress at the Tetra Zone utilizing one diamond drill."

Looking Ahead

With the Fall 2025 Tetra Zone programme complete, F3 is advancing into its follow-up drill campaign with zone geometry and continuity data from PLN25-219A and PLN25-221 in hand. The current programme is focused on further defining the east-west extent and structural controls of the Tetra Zone on the Broach Property. The PLN Project, located in proximity to Paladin Energy's Triple R and NexGen Energy's Arrow deposits, sits in what the company describes as an area "poised to become the next major area of development for new uranium operations in northern Saskatchewan." Additional drill results from the ongoing programme are expected as work progresses.

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